<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>扩展函数</title>
</head>
<body>

	<script>
		let a='今天天气不错一起去溜达'
		console.log(a.startsWith('今天'));
		console.log(a.startsWith('明天'));
		console.log(a.endsWith('溜达'));
		console.log(a.endsWith('没人'));
		console.log(a.includes('天气'));
		console.log(a.includes('晴天'));
		console.log('ha'.repeat(5));
		console.log('02-17'.padStart(10,'2020-01-01'))
		console.log('武汉加油'.padEnd(10,'中国加油'))
   	</script>

</body>
</html>